1) - 2 1/6 + 3 1/15 = - 2 5/30 + 3 2/30 = 3 2/30 - 2 5/30 = 2 32/30 - 2 5/30 = 27/30 =
= 9/10 = 0,9
2) - 4 7/9 + 5/6 = - 4 14/18 + 15/18 = 15/18 - 4 14/18 = 15/18 - 86/18 = - 71/18 =
= - 3 17/18
3) 5 2/7 + (- 3 7/8) = 5 16/56 - 3 49/56 = 4 72/56 - 3 49/56 = 1 23/56